Longitude moved east and west from the prime meridian.
Following Hipparchus he divided the equator into 360 drawing his prime meridian through the Fortunate Islands (Canaries).
The 1884 International Prime Meridian Conference established an international standard time system.
He was a member of the International Prime Meridian and Time Conference in 1884, and of the Board of Fortifications in 1885-1886; was superintendent of the Naval Academy from 1886 to 1890; and was promoted to captain and served as delegate at the International Maritime Conference at Washington in 1889.
He was British delegate to the International Prime Meridian Conference at Washington in 1884, when he also attended the meetings of the British Association at Montreal and of the American Association at Philadelphia.